Furnace humidifier



May 13, 1969 5. J. POLLICK FURNACE HUMIDIFIER Filed April 2, 1968 INVENTOR.

6714/1 10 J. Pall/(K BY M W, M M

AT TOR/VEVS United States Patent 3,443,559 FURNACE HUMIDIFIER Stanley J. Pollick, 5268 Botsford, Warren, Mich. 48092 Continuation-impart of application Ser. No. 604,675, Dec. 27,1966. This application Apr. 2, 1968, Ser. No. 724,672

Int. Cl. F24h 9/00; F23d 13/24 US. Cl. 126-113 15 Claims ABSTRACT OF THE DISCLOSURE This application is a continuation-in-part of application Ser. No. 604,675 filed Dec. 27, 1966, now abandoned.

This invention relates to humidifiers and particularly to furnace humidifiers for use with furnaces that have hot exhaust gases.

Among the objects of the invention are to provide a furnace humidifier which will produce substantial quantities of water vapor; which will recover some of the thermal losses normally existent in the hot gases of the furnace; which is compact, simple, low in cost, does not utilize outside energy such as a motor or the like and has no moving parts.

Basically, the humidifier disclosed herein comprises a closed casing having a water inlet and a steam outlet which is positioned in the path of the hot gases of the furnace. A plurality of tubes extend horizontally from the casing and have closed outer ends, the tubes being substantially at the level of the water in the casing. In addition, a plurality of open ended tubes extend generally horizontally to the casing and are surrounded by water within the casing. The hot gases flowing over the two sets of tubes produces steam which passes into the hot air flue of the furnace.

In the drawings:

FIG. 1 is a part sectional partly diagrammatic elevational view of a furnace embodying the invention.

FIG. 2 is a fragmentary sectional view on an enlarged scale of a portion of the furnace shown in FIG. 1.

FIG. 3 is a fragmentary sectional view taken along the line 3--3 in FIG. 2.

FIG. 4 is a sectional view taken along the line 44 in FIG. 2.

Referring to FIG. 1, the furnace is shown in semidiagrammatic fashion and includes a fire box 11 and a plenum 12. Furnace 10 further includes a sloping wall 13a and a vertical wall 13b defining a flue gas exhaust chamber 130. A horizontal partition 12a separates fire box 11 from plenum 12 whereby the heat is transferred from the hot gases of combustion from the fire box 11 to the air in the plenum 12. It can be understood that the air movement through the plenum 12 is forced by fans or otherwise in accordance with well known art. Fire tubes 30 extend from fire box 11 to the flue gas chamber through the plenum so that the hot gases pass to flue 16.

In accordance with the invention, humidifier 15 embodying the invention is positioned in the flue gas chamber in the path of the hot exhaust gases as they move out- 3,443,559 Patented May 13, 1969 wardly to the flue 16. The humidifier 15 comprises a cylindrical horizontally extending casing 17 which has a water inlet 18 at one end and a steam outlet 19 from the upper surface thereof that extends through the wall 13 into the plenum 12. Water is supplied through a float control 20 and check valve 21 to the inlet 18. A solenoid valve 22 controlled by a humidistat 23 prevents the passage of water to the casing 17 in the event that the humidity in the area being heated reaches a predetermined value. An air inlet 19a has a downwardly facing opening 19 at its free end which is in the plenum and extends to the top of the casing 17, at the end of casing 17 opposite to the end at which the outlet 19 is connected.

The humidifier 15 further includes a plurality of hozizontally extending closed end pipes 24 that extend laterally outwardly from the casing 17 into fire tubes 30 and have their open ends 25 communicating with the interior of the casing 17 and their free ends 26 closed. The pipes 24 are positioned at a point in the casing 17 such that their longitudinal axes lie at the water level substantially at the midpoint of the vertical height of the casing 17. Each of the pipes 24 is elongated in cross section with the greater dimension extending vertically as shown in FIG. 4. The humidifier 15 further includes a plurality of tubes 27 that have their ends open and extend entirely through the casing so that the tubes are surrounded by water as shown in FIGS. 2 and 3. If desired, an overflow pipe 28 may be provided at the end of the casing 15 to provide for overflow in the event of failure of the float control.

In use, the hot gases passing upwardly through fire tubes 30 across the tubes 24 and through the tubes 27 as they move to the flue 16 cause the water in the tubes 24 and in the casing 17 to be continuously vaporized and pass upwardly and outwardly as steam to the steam outlet pipe 19. Passage of the hot gases through the pipes 27 further facilitates the heating of the water and the creation of the steam. The hot air flowing through inlet pipe 19a passes over the steam in the casing 17 and entrains moisture therein and thereafter passes outwardly through outlet 19 to the plenum 12.

It has been found that the humidifier produces substantial quantities of steam and, at the same time, removes heat from the hot exhaust gases.

I claim:

1. In a furnace, the combination comprising a fire box,

a plenum exposed to the hot gases of the fire box,

means for directing the hot gases from the fire box to the flue,

a humidifier positioned in said last-mentioned means comprising a closed casing having a water inlet,

a steam outlet from said casing,

a plurality of generally horizontally extending tubes connected to said casing at the water level and extending outwardly of said casing,

the free ends of said tubes being closed,

a plurality of open ended tubes extending entirely through said casing in the area in which water is provided whereby portions of said tubes are completely surrounded by water,

and means for maintaining the water at a predetermined level in said casing.

2. The combination set forth in claim 1 wherein all of said tubes are generally parallel to one another.

3. The combination set forth in claim 1 wherein said closed end tubes have an elongated cross section wlth the greatest dimension extending vertically.

4. The combination set forth in claim 1 wherein said casing is circular in cross section.

5. The combination set forth in claim 1 wherein each of said open ended tubes is substantially circular in cross section.

6. The combination set forth in claim 1 wherein said close ended tubes extend horizontally to one side of said casing only.

7. The combination set forth in claim 1 wherein said hot gas directing means comprise fire tubes,

said closed end tubes of said humidifier extending into the upper ends of said fire tubes.

8. The combination set forth in claim 1 wherein said casing includes an air inlet having one end thereof communicating with said casing and the other end thereof extending into said plenum.

9. For use in a furnace,

a humidifier adapted to be positioned in the path of hot gases comprising a closed casing having a water inlet,

a steam outlet from said casing,

a plurality of generally horizontally extending tubes connected to said casing at the water level and extending outwardly of said casing,

the free ends of said tubes being closed,

and a plurality of open ended tubes extending entirely through said casing in the area in which water is provided whereby portions of said tubes are adapted to be completely surrounded by water.

10. The combination set forth in claim 9 wherein said tubes are generally parallel to one another.

11. The combination set forth in claim 9 wherein said closed end tubes have an elongated cross section with the greatest dimension extending vertically.

12. The combination set forth in claim 9 wherein said casing is circular in cross section.

13. The combination set forth in claim 9 wherein each of said open ended tubes is substantially circular in cross section.

14. The combination set forth in claim 9 wherein said close ended tubes extend horizontally to one side of said casing only.

15. The combination set forth in claim 9 wherein said casing has an air inlet having one end thereof connected to said casing and the other end thereof adapted to extend outwardly into a plenum.

References Cited UNITED STATES PATENTS 1,453,137 4/1923 Hockins 126-113 2,069,145 1/1937 Hastings et a1. 126-113 X 2,651,293 9/1953 Bottom 126-113 X 3,303,837 2/1967 Ritter 126-113 JAMES W. WESTHAVER, Primary Examiner.

US. Cl. X.R. 126-350 

